一种低熔点含能化合物的合成、表征与脉冲超声辅助萃取的研究

以甲基肼、双氰胺为起始原料，经缩合环化、氧化两步反应合成1-甲基-3,5-二硝基-1,2,4-三唑(DNMT)。精制后，熔点为93~95 ℃，用核磁光谱(¹H,¹³C NMR)、红外光谱、质谱分析、元素分析对其结构进行了表征。用差热分析法研究了DNMT的热分解性能, 热分解峰温281.5 ℃. 分析了DNMT的合成反应机理。同时，改善了产物后处理精制工艺，改用热的乙酸乙酯采用脉冲超声辅助液液萃取(ULLE)法萃取目标产物，系统地研究了超声功率、时间、温度、乙酸乙酯体积和萃取次数因素对萃取效率的影响，进而对萃取条件进行了最优化。结果表明：ULLE法有利于高效地获取高纯度目标产物；产物总收率由16.8%提高到52.8%，高效液相色谱纯度≥98.68%.

Research on the Synthesis,Characterization and Pulse Ultrasnic-assisted Extraction of a Low Melting Point Energetic Compound

1-Methyl-3,5-dinitro-1,2,4-triazole (DNMT) is synthesized from dicyandiamide and methyl hydrazine via a two step procedure (condensation and oxidation).After purification,the melting point is 93 ～ 95 ℃.The structure of the target DNMT is characterized by 1H,13C NMR,FT-IR,MS and elemental analysis.The thermal stability is studied by TG-DTA.The result shows that the thermal decomposition temperature is 281.5 ℃.The reaction mechanism of DNMT in synthesis is primarily discussed.The posttreatment technology is improved,and the method of ultrasonic-assisted liquid-liquid extraction (ULLE) is used to extract the target product with thermal ethyl acetate as extractant.The influence of extraction parameters,such as volume,temperature of extraction solvent,extraction time,etc.,on extraction efficiency are investigated.The result shows that ULLE method is conducive to efficiently obtain highly pure product (≥98.68％,HPLC),and the overall yield is raised to 52.8％.